boiling in inactivating the toxic substances in the seeds. Trypsin inhibitors have been implicated in reducing
The toasted samples still retain greater amount of the protein digestibility (Liener, 1976).
antinutritional factors. This result agrees with the earlier In spite of the non significant (P >0.05) difference in the
observations by Udedibie et al. (1994) on the effect of dry
heat treatment on the nutritive value of legume seeds.
The feed intake of broilers on diet containing raw PSM
was significantly (p < 0.05) higher than those containing
processed PSM, this however did not result in higher
weight gain. The birds apparently increased their intake
of the raw diet to meet their nutrient requirement from a
diet that contained anti metabolites. This suggests that
nutrients in the raw PSM were not as available as they
were in the processed diets (Amaefule and Obioha,
2001). The presence of antinutritional factors in raw PSM
diets may also have increased the rate of gastric
evacuation in the birds. High rates of gastric evacuation
is usually compensated for by increased feed intake
(Aduku, 1993).
Feed conversion ratio and protein efficiency ratio were
significantly (P>0.05) better for those on processed diets
than those on raw PSM. The superior feed conversion
ratio of birds on processed diets suggests that there
enhanced availability, digestion, absorption and
utilization of the nutrients in the processed seeds by
broilers. Similar observations have been reported by
Akinmutini et al. (2003) and Akpodiete et al. (2001).
Results of the digestibility studies (Table 5) showed that
except for crude protein, there was no significant
(P>0.05) in the digestibility of other nutrients among the
birds on processed and raw PSM. The reduction in
crude protein utilization may be ascribed to the presence
of the antinutritional substances contained in raw PSM.
performance of the broilers in the three differently
processed PSM, broilers fed diets containing pigeon
pea seeds boiled with potash recorded higher values in
the performance parameters measured. This
improvement over diets containing boiled and toasted
PSM could be associated with complete elimination of
the antinutritional factors, which enhanced protein and
energy digestibility and utilization. However the exact
mode of action of potash on the antinutritional factors in
the pigeon pea is not clear.
Conclusion: The results obtained from this study
indicates that all the processing methods viz; boiling,
boiling with potash and toasting are effective in reducing
the antinutritional factors in pigeon pea seeds in broiler
rations. It appears that boiling with potash will further
improve the nutritional value of pigeon pea seeds.